There is, however, evidence from quasi experimental research that concerted and sometimes low-cost interventions are able to greatly reduce the hospital transmission and prevalence of multi-drug resistant organisms (MDROs), resulting in improved patient outcomes. Improved hand hygiene(HH) is widely believed to be the single most effective intervention. However a 2010 Cochrane review has highlighted the lack of methodologically sound research evaluating interventions to improve HH: only four studies met the minimum inclusion criteria and only one such study came from a lower or middle income country (a randomised trial of an educational intervention for nurses in China). Moreover, a recent review has identified a need for stronger evidence linking improved HH compliance with reductions in HCAIs (currently such evidence is based only on observational studies).